In general, an electric vehicle is a vehicle that is driven by an electric motor using a high-voltage battery, and the high-voltage battery is charged by coupling a charging connector for a charging station to a charging inlet in the electric vehicle. Then, when the charging connector is inserted into and electrically connected to the charging inlet, the high-voltage battery of the electric vehicle is charged by supplying the electric power of the charging station to the high-voltage battery of the electric vehicle after a charging parameter (a voltage or a current) is set through mutual communication. The electric vehicle includes an electric vehicle (EV) and a plug-in hybrid electric vehicle (PHEV).
Recently, chargers that may supply a high output (e.g., 1000 V/200 A) to charging stations have been installed to decrease the charging time of the electric vehicles. When a high current is applied form the high-output charger to the inlet and the cable of the electric vehicle for a substantial period of time, excessive heat may be generated in the inlet and the cable of the electric vehicle, and accordingly, a fire may occur in the electric vehicle since the heat may deteriorate the durability of the inlet and may burn or otherwise damage the cable.
The traditional overheating preventing technology is a technology for preventing overheating of the charging connector for a charging station or preventing overheating of the high-voltage battery mounted on the electric vehicle, and a technology for preventing a charging inlet provided in an electric vehicle has not be suggested. In particular, a technology for estimating the temperature of a charging inlet in an electric vehicle with a high precision based on a charging voltage, a charging current, and a charging time also has not be suggested.